Capability · Comparison
Milvus vs Weaviate
Milvus and Weaviate are two of the most deployed open-source vector databases. Milvus (Zilliz) is purpose-built for the largest scales — billions of vectors, multi-tenant, GPU-accelerated indexing. Weaviate is a modular vector DB with strong hybrid search (BM25 + vector), a rich module ecosystem (generative, multi2vec-*, rerankers), and multi-tenant support.
Side-by-side
| Criterion | Milvus | Weaviate |
|---|---|---|
| Max scale tested | Billions of vectors | Hundreds of millions |
| Hybrid search (BM25 + vector) | Yes (since 2.4) | First-class |
| GPU indexing | Yes — CAGRA, GPU_IVF_PQ | No |
| Module ecosystem | Smaller | Large — generative, rerank, multi2vec |
| Multi-tenancy | Yes | First-class, per-tenant shards |
| License | Apache 2.0 | BSD-3 |
| Managed service | Zilliz Cloud | Weaviate Cloud Services |
| Primary API | gRPC + Python/Go/Java/Node SDKs | GraphQL + REST + gRPC |
Verdict
Pick Milvus when you need to scale past a billion vectors, when GPU indexing is a real requirement, or when you're running multi-region distributed deployments. Pick Weaviate when you need first-class hybrid search, multi-tenant SaaS-shaped workloads, or the built-in generative / reranker modules. For a RAG app of tens of millions of chunks with hybrid search, Weaviate is typically the faster setup. For frontier-scale retrieval research, Milvus.
When to choose each
Choose Milvus if…
- You're scaling to a billion+ vectors.
- GPU-accelerated index building matters.
- You have a strong ops team and want tunable distributed deployments.
- Your workload is pure vector similarity with filtered search.
Choose Weaviate if…
- You need strong hybrid search out of the box.
- Multi-tenant SaaS shape fits your product.
- You want built-in modules for generation or reranking.
- You value a GraphQL API and cleaner developer UX.
Frequently asked questions
Which is faster?
Depends on workload. Milvus is typically faster at raw ANN at very high scale with GPU index; Weaviate is typically faster on hybrid BM25+vector queries. Benchmark on your query shape.
Can I self-host both?
Yes — both are open source and ship Helm charts. Milvus has a cleaner multi-pod Kubernetes story; Weaviate's single-binary deployment is easier for getting started.
Which has better Python ergonomics?
Weaviate — the Python client v4 has a very clean Pythonic API. Milvus's pymilvus works well but is lower-level.
Sources
- Milvus — docs — accessed 2026-04-20
- Weaviate — docs — accessed 2026-04-20